1. Field of the Invention
The present invention relates generally to a liquid crystal display apparatus, and more particularly to a liquid crystal display apparatus which is capable of preventing a break due to a crack caused during a manufacturing process.
2. Discussion of the Background
A liquid crystal display apparatus, an important man-machine communications device, is used in a variety of electronic devices such as electronic watches, personal digital assistant (PDA) systems, word processors, copying machines, facsimile machines, and so on. In the liquid crystal display apparatus, a polymer substrate has been widely employed in place of a glass substrate. Utilizing a polymer substrate is a known technique and is described in, for example, Japanese Laid-Open Patent Application No. 07-043697 (1995) referring to an exemplary structure of a liquid crystal display apparatus shown in FIG. 1. The liquid crystal display apparatus of FIG. 1 has a typical structure which includes a pair of polymer substrates 1 and 2, indium-tin oxide (ITO) electrodes 3 and 4, a sealing member 5, a liquid crystal 6, and polarizing seals 10 and 11. The ITO electrodes 3 and 4 are bonded on the sides of the polymer substrates 1 and 2 to face each other. The sealing member 5 is deposited between the ITO electrode films 3 and 4 around the edge of the ITO electrode film 3 so that the liquid crystal 6 is sealed therein. In the liquid crystal display apparatus having the structure mentioned above, the liquid crystal 6 is energized to display information in a form of alphanumeric symbols, for example, by applying an electrical current to the ITO electrodes 3 and 4.
In general, a liquid crystal display apparatus having the above-described structure is used as part of an electronic device (not shown), for example, and is therefore mounted inside a housing or the like of the electronic device. FIG. 1 shows a connecting portion of the electronic device and the liquid crystal display apparatus. The electronic device includes a connecting member 7, a solder 8, bumps 8a, and an electrode 9. The connecting member 7 is extended from a circuit substrate (not shown) or the like of the electronic device to supply power to the liquid crystal display apparatus. For this purpose, an extension 2a is extended from the polymer substrate 2 and an electrode extension 4a is extended from the ITO electrode 4 along the extension 2a.
To electrically connect the electrode extension 4a to the connecting member 7, the electrode extension 4a is typically pressed against the connecting member 7 and is then soldered with the solder 8, which is deposited together with the bumps 8a between the electrode 9 bonded on the bottom of the connecting member 7 and the electrode extension 4a.
However, the above-mentioned way of connecting the liquid crystal display apparatus to the electronic device provides a stress to the electrode extension 4a on the electrode 4 or to the electrode extension 4a at a position under the sealing member 5, which may generate a crack 12. This may eventually cause a failure of electrical connection between the liquid crystal display apparatus and the circuit substrate of the electronic device. As a result, the liquid crystal cannot properly display information. This kind of error may be caused not only when the electrode extension 4a is connected to the connecting member 7 using heat and pressure, but also when the electrode extension 4a receives an excessive stress during the installation of the liquid crystal display to the electronic device.
One technique for preventing this problem is to extend the polarizing seal 11 to cover the length of the extension of the polymer substrate 2a so as to support the electrode extension 4a. However, this technique is not sufficient because such a technique would be effective only after the extended polarizing seal 11 is attached and the electrode extension 4a may receive a stress and may be bent, as shown by dotted lines in FIG. 2, before the extended polarizing seal 11 is attached.